Improved Tree-Ring Archives in the Forest–Steppe Zone of Southern Western Siberia

This paper presents a new network of tree-ring width (TRW) chronologies completed for ribbon pine forests, the Ob region pine forest, and pine forests in the south of Western Siberia (Altai krai and Novosibirsk oblast) and describing the growth of annual ring widths of the Scots pine (Pinus sylvestris L.). Measurements of annual ring parameters are made on high-resolution digital images. A statistically significant relationship (from 0.83 to 0.46) is observed between all tree-ring series (maximum distance between points 330 km). On the basis of cluster and correlation analysis, the local steppe and forest-steppe chronologies were combined into three regional chronologies (Pl 5, 6, and 7). A comparison of parameters of chronologies in Altai krai and Novosibirsk oblast shows that the border between regions (and in physiographic terms, the border between southern and middle forest steppe) is conditionally a kind of line dividing TRW chronologies into groups characterized by different sensitivity of radial growth to changes in environmental factors. At the same time, chronologies from stony slopes (spurs of the Kolyvan ridge) have maximum sensitivity. The results of the study allow us to compare the dendroindication potential of pine forests of the study area and neighboring regions (the Urals, Siberia, and Russian far East). The importance of selecting sample plots in ribbon pine forests and Ob region pine forests is shown, since the use of a random set of chronologies will not allow one to correctly reconstruct the climatic conditions of tree growth.